Exemplary embodiments of the present invention relate generally to regenerative turbine pumps of the type that are used to pump fuel from a fuel tank to an engine of a motor vehicle. More particularly, the invention pertains to an outlet port of a regenerative turbine fuel pump.
Automotive impeller style fuel pumps use a rotating impeller contained within a pump section pocket to pump fuel to the engine. Upper and lower plates are used to form the pocket and they are held within a very close proximity to the impeller surface to minimize fuel leakage from high to low pressure areas. Each plate contains a flow channel that function as parallel pumping chambers that are powered by the rotating impeller. The fluid enters the flow channels through an inlet port located at the beginning of the lower plate flow channel and a single outlet port is located at the end of the upper outlet plate flow channel to exhaust the flow. As the fluid exits the flow channel, the fluid in the lower flow channel flows through the rotating impeller and mixes with the fluid in the upper channel. This mixing creates turbulence and backflow that imparts drag on the impeller blades and reduces pump efficiency.
Accordingly, is desirable to provide a fuel pump design that addresses this turbulence and backflow created by the fluid mixing.